I honestly think he needs to buy it with cash. Alternatively, he needs to maybe start converting his wages into bank fiat so it looks like there is regular income in his bank but this is just stupid with so much opportunity cost.

This I think, is the kicker. Getting a mortgage doesn't rely on your wealth, it depends on how well they think you can pay the monthlys AND your other expenses... they do an assessment for you.

You may get paid enough, but if you don't have capital for a deposit then they'll still reject you.

IMO, If you want to be sovereign, buy a house outright or rent until you can. It's hard to be part of society while being poor or while being sovereign.